Camera pens are known to include a miniaturized camera for capturing images of a product surface, see e.g. US2004/0179000, WO2005/057471 and US2003/0075673.
Generally, the camera is designed as a package of a large number of separate components, such as a CCD sensor, one or more imaging lenses, an aperture stop, a radiation filter, an illuminating LED, optics for redirecting/shaping the illuminating radiation emitted from the LED, etc. Since these components are both numerous and small, assembly work may be difficult and time-consuming. Further, the camera may need to be designed with strict assembly tolerances to avoid problems with tolerance stack-up. There is thus a need for a camera design that is simple to assemble with high precision, even if manufactured in small dimensions.
Prior art pens have a camera which is customized to each particular pen design. The camera design involves a complex trade-off between allowable pen orientations, depth of field, field of view, location of field of view with respect to the stylus tip, illumination brightness, assembly and manufacturing tolerances, etc. Even minor changes in pen design and/or use may thus result in extensive development work to adapt the camera. Clearly, it would be desirable to relax the high requirements on the camera design.
Electronic pens may include a stylus sensor which indicates to a processor in the pen that the pen stylus is in contact with a product surface, see e.g. US2005/0030297. Generally, the stylus sensor is responsive to a longitudinal movement of the stylus. Thus, the pen must be designed to allow the stylus to be longitudinally movable. If the pen is used for writing, the movement of the stylus may impair the user's writing experience. Further, unless special care is taken to seal off the front end of the pen where the stylus protrudes, moisture and dust may enter the pen. There is thus a need to for alternative contact sensors in electronic pens.
An electronic pen is designed for a specific purpose, i.e. to provide certain functionality. If an alternative or additional functionality is desired, the user needs to buy another electronic pen. One solution would be to provide a multi-purpose pen, but such a pen will be more expensive and it is still possible that the desired functionality is lacking. There is thus a need for a simple and efficient way of adding functionality to an electronic pen.
Electronic pens also include consumables that may need to be replenished from time to time, including writing ink and power. Replenishment may require the user to bring along additional devices, such as spare cartridges of ink or a battery charger. If these devices are forgotten, which is quite likely, the pen eventually becomes inoperable. There is thus a need to facilitate the replenishment of a consumable in an electronic pen.